Valve including multilayer wear plate

ABSTRACT

A valve is provided and includes a component including a surface and a wear plate including a surface disposed in sliding engagement with the surface of the component. The surface of the wear plate includes a corrosion resistant substrate, a secondary layer disposed on a surface of the corrosion resistant substrate, a noble metal layer disposed on a surface of the secondary layer and a tertiary layer disposed on a surface of the noble metal layer.

BACKGROUND OF THE INVENTION

Aspects of the present invention are directed to a valve and, moreparticularly, to a valve including a multilayer wear plate.

Multilayer articles are used in a wide variety of applications wheredifferent metals are utilized to provide the articles with differentsets of properties. For example, an article can be formed from steel toprovide strength, hardness and rigidity. For extreme environments, suchas high temperature and/or corrosive or oxidizing environments,stainless steel or more exotic alloys can provide resistance tocorrosion or oxidation.

In some applications, such as where an article has a metallic wearsurface that is in sliding engagement or contact with the surface ofanother component, the surface of the metallic article may not provideadequate lubricity to meet the wear needs of the application. In suchcases, a wear layer can be disposed on the appropriate surface of thearticle to provide the desired wear surface properties. Polymericlayers, such as layers of fluoropolymers may be used for such wearsurface applications. However, polymers are often not suitable for hightemperature applications like those found in aircraft air managementsystems. Indeed, valves in these systems are required to be operable atelevated temperatures in excess of 300° C. and with high vibration modeswith little or no lubrication. As such, wear out of critical slidingcomponents in these valves (i.e., the valve wear plate) is common andcan degrade valve performance.

BRIEF DESCRIPTION OF THE INVENTION

According to an exemplary embodiment, a valve is provided and includes acomponent including a surface and a wear plate including a surfacedisposed in sliding engagement with the surface of the component. Thesurface of the wear plate includes a corrosion resistant substrate, asecondary layer disposed on a surface of the corrosion resistantsubstrate, a noble metal layer disposed on a surface of the secondarylayer and a tertiary layer disposed on a surface of the noble metallayer.

In another exemplary embodiment, a wear plate of a valve including acomponent is provided. The wear plate includes a surface disposed insliding engagement with a surface of the component. The surface of thewear plate includes a substrate including one or more of corrosionresistant steel, Inconels™, Incoloys™, Hastelloys™, Waspaloys™, Elgiloy™and Haynes™ alloys, a secondary layer disposed on a surface of thesubstrate, a noble metal layer disposed on a surface of the secondarylayer and a tertiary layer disposed on a surface of the noble metallayer.

In yet another exemplary embodiment, a butterfly valve is provided andincludes a valve housing formed to define a bore, a disc and shaft setoperably disposed in the bore, the disc and shaft set including a wearplate disposed in abutment with a shim and an actuator coupled to thedisc and shaft set to thereby cause the disc and shaft set to rotateabout a long axis of the shaft such that a surface of the wear plateslidably engages with a flange surface of the shaft. The surface of thewear plate includes a corrosion resistant substrate, a secondary layerdisposed on a surface of the corrosion resistant substrate, a noblemetal layer disposed on a surface of the secondary layer and a tertiarylayer disposed on a surface of the noble metal layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawing in which:

FIG. 1 is a schematic representation of a cross-sectional view of anembodiment of a multilayer article;

FIG. 2 is a schematic representation of a cross-sectional view ofanother embodiment of a multilayer article;

FIG. 3 is a cross-sectional view of a valve including a multilayer wearplate;

FIG. 4 is an enlarged view of a portion (encircled) of the valve of FIG.3; and

FIG. 5 is a plan view of the wear plate of the valve of FIGS. 3 and 4.

DETAILED DESCRIPTION OF THE INVENTION

To resolve the issues of wear noted above for a valve including a wearplate, such as a pneumatic butterfly valve, the wear plate load bearingsurfaces are coated with a low friction silver coating. The silvercoating reduces friction and wear that result from thrust loads on theshaft during operation. For ease of manufacturing and assembly, thesilver coating is applied to all surfaces of the wear plate and, incombination with the hard-face coatings and substrate materials thatform the remaining components of the valve, lead to a robust system.

A simplified multilayer article is schematically shown in an explodedcross-sectional view in FIG. 1, in which article 10 includes a substrate12. The substrate 12 may be formed of corrosion resistant material, suchas one or more of stainless steel, Inconels™, Incoloys™, Hastelloys™,Waspaloys™, Elgiloy™, and Haynes™ alloys. A secondary metallic layer 14is disposed on the substrate 12 and may be formed of nickel, copper orother similar materials by electroplating, thermal spraying or othersimilar processes. A noble metal layer 16 is disposed on the secondarymetallic layer 14. The noble metal layer 16 may be formed of a noblemetal selected from the group including gold, platinum, palladium,rhodium and combinations thereof by electroplating, thermal spraying orother similar processes. A tertiary metallic layer 18 is disposed on thenoble metal layer 16 and may be formed of silver by electroplating,thermal spraying or other similar processes.

Another embodiment is shown in FIG. 2. In FIG. 2, article 20 includes asubstrate 12. The substrate 12 may be formed of corrosion resistantmaterial, such as one or more of stainless steel, Inconels™, Incoloys™,Hastelloys™, Waspaloys™, Elgiloy™, and Haynes™ alloys. A secondarymetallic layer 14 is disposed on the substrate 12 and may be formed ofnickel, copper or another similar material by electroplating, thermalspraying or other similar processes. A noble metal layer 16 is disposedon the secondary metallic layer 14. The noble metal layer 16 may beformed of a noble metal selected from the group including gold,platinum, palladium, rhodium and combinations thereof by electroplating,thermal spraying or other similar processes. A tertiary metallic layer18 is disposed on the noble metal layer 16 and may be formed of silverby electroplating, thermal spraying or other similar processes. Thetertiary metallic layer 18 may include strike layer 18′. Strike layer18′ may be formed of silver and is disposed as a relatively thin layerbetween the noble metal layer 16 and a main portion of the tertiarymetal layer 18.

The strike layer 18′ may be added to improve adhesion between thetertiary metallic layer 18 and the undercoatings. The strike layer 18′is substantially thinner than the tertiary metallic layer 18 and may beabout 0.1 to about 2.5 μm thick (about 0.000004 to 0.0001 inches).

The substrate 12 of FIGS. 1 and 2 can be fabricated from any known typeof corrosion resistant materials in order to provide the article withdesired properties. These corrosion resistant materials may include butare not limited to austenitic stainless steel (e.g., stainless steelalloys from the 300 series such as SS304, SS306, SS316), martensiticstainless steel alloys including precipitation-hardened martensiticstainless steel, ferritic stainless steels and combinations thereof.

The secondary metallic layer 14 of FIGS. 1 and 2 may include nickel andenhances compatibility and adhesion between the substrate 12 and theoverlying layer(s). In an exemplary embodiment, the secondary metalliclayer 14 may be formed by electroplating, thermal spraying or othersimilar processes as a strike layer and has a thickness of about 0.25 μmto about 25 μm (about 0.00001 inches to about 0.001 inches). In anotherexemplary embodiment, the secondary metallic layer 14 includes pure ornearly pure nickel.

The tertiary metallic layer 18 may include silver. Silver can providesufficient lubricity for use as a wear layer (as used herein, “wearlayer” means a surface layer that, during use, is in slidable engagementwith another surface), and in an exemplary embodiment, the tertiarymetallic layer 18 is provided as a wear layer. In another exemplaryembodiment, the tertiary metallic layer 18 has a thickness of about 0.25μm to about 250 μm (about 0.00001 inches to about 0.01 inches). Inanother exemplary embodiment, the tertiary metallic layer 18 includespure or nearly pure silver.

The noble metal layer 16 includes a noble metal selected from the groupincluding gold, platinum, palladium and rhodium and combinationsthereof. Although the present invention and the scope thereof is notbound by any particular embodiments, as temperature increases, thesolubility of oxygen in silver may increase and thus exposure to anoxygen-containing atmosphere (i.e., air at elevated temperatures) canallow oxygen to diffuse through the silver of the tertiary metalliclayer 18, as described above. The increased solubility of oxygen insilver at elevated temperatures can allow oxygen to diffuse through thesilver and oxidize the materials of the underlying secondary metalliclayer 14, which may lead to blistering and/or delamination of thetertiary metallic layer 18.

The noble metal layer 16 thus provides a barrier to prevent dissolvedoxygen from reaching the secondary metallic layer 14, while itself beingresistant to oxidation. In an exemplary embodiment, the noble metallayer 16 is sufficiently resistant to oxidation and/or penetration byoxygen so as to prevent blistering and/or delamination of the tertiarymetallic layer 18 when the article 10, 20 is exposed to a temperature ofat least 510° C. (950° F.) for about 64 hours and for an additional 16hours at about 629° C. (1164° F.). In accordance with embodiments, thenoble metal layer 16 may be formed of gold, platinum, palladium, rhodiumand combinations thereof. In another exemplary embodiment, the noblemetal layer 16 has a thickness of about 0.7 μm to about 1.3 μm (about0.00002 to about 0.00005 inches).

As mentioned above, the tertiary metallic layer 18 can be a wear layeron an article to be used for high temperature applications. The articlecan be used for any application requiring a wear layer where the articlewill be subject to exposure to an oxygen-containing atmosphere (e.g.,air) at high temperatures such as in moving contact parts on valves usedin high-temperature environments (e.g., combustion engine-mountedvalves), mechanical or electromechanical actuator devices used inhigh-temperature environments, and the like.

With reference to FIGS. 3-5, the articles 10, 20 may be provided for usein a butterfly valve 100. As shown in FIGS. 3 and 4, the butterfly valve100 includes a valve housing 101, a disc and shaft set 102, an actuator130 and a thrust plate 131. The valve housing 101 is formed to define abore 103 that extends through the valve housing 101 in a longitudinaldimension. The disc and shaft set 102 includes a disc 104 that iscoupled to sidewalls of the bore 103 and a butterfly shaft 105 that issupportively coupled with the disc 104. The disc and shaft set 102 isoperably disposed in the bore 103 and further includes a wear plate 110(see FIG. 4) that is disposed in abutment with one or more shim(s) 120(see FIG. 4) of the valve housing 101.

The actuator 130 is coupled to the disc and shaft set 102. The thrustplate 131 defines a cavity in which a thrust plug 132 is disposed. Thethrust plug 132 is affixed to the thrust plate 131 and is coupled to anend of the butterfly shaft 105 via a solid disc 133. The actuator 130 isthus configured to cause the disc and shaft set 102 to rotate about along axis of the disc 104, which is defined along the longitudinaldimension.

The wear plate 110 is provided substantially similarly as the articles10, 20. The wear plate 110 is disposed between a shoulder of thebutterfly shaft 105 and the one or more shim(s) 120. As such, when thedisc and shaft set 102 rotate about the long axis of the disc 104, asurface 112 of the wear plate 110 slidably engages with a surface of theone or more shim(s) 120. In accordance with embodiments, the surface 112of the wear plate 110 includes the features of the articles 10, 20described above. Thus, the surface 112 includes the substrate 12, thesecondary metallic layer 14, the noble metal layer 16 and the tertiarymetallic layer 18. In accordance with further embodiments, the substrate12 may include corrosion resistant steel, the secondary metallic layer14 may include nickel, the noble metal layer 16 may include at least oneor more of gold, platinum, palladium, rhodium and combinations thereofand the tertiary metallic layer 18 may include a strike layer 18′ andmay be formed of silver. In addition, the noble metal layer 16 may beabout 0.7 μm to about 1.3 μm (about 0.00002 to about 0.000050 inches)thick and the tertiary metallic layer may be about 0.25 μm to about 250μm (about 0.00001 to about 0.01 inches) thick.

As shown in FIG. 5, the wear plate 110 includes a body 115 havingopposing planar faces. The body 115 is formed to define an aperture thatextends from face-to-face. The wear plate 110 further includes opposingflanges 116 that extend radially outwardly from an outer diameter of thebody 115 at opposite sides thereof. The flanges 116 serve to preventrotation with respect to the shim(s) 120.

With the surface 112 of the wear plate 110 formed in this manner, thenoble metal layer 16 serves to protect the secondary metallic layer 14from oxidation or other similar effects due to dissolved oxygendiffusing through the tertiary metallic layer 18 which, if allowed toreach the secondary metallic layer 14, would ultimately cause thetertiary metallic layer 18 to blister during operation. This protectionagainst oxidation or the other similar effects is provided even atelevated temperatures and pressures and in high vibration environments,such as those associated with operational aircraft gas turbine engines.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

The invention claimed is:
 1. A valve, comprising: a component includinga surface; and a wear plate including a surface disposed in slidingengagement with the surface of the component, the surface of the wearplate comprising: a corrosion resistant substrate; a secondary layerdisposed on a surface of the corrosion resistant substrate; a noblemetal layer disposed on a surface of the secondary layer; a tertiarylayer disposed on a surface of the noble metal layer; and a strike layerinterposed between the noble metal layer and the tertiary layer.
 2. Thevalve according to claim 1, wherein the corrosion resistant substratecomprises steel.
 3. The valve according to claim 1, wherein thesecondary layer comprises nickel, copper or a combination thereof. 4.The valve according to claim 1, wherein the noble metal layer comprisesat least one or more of gold, platinum, palladium and rhodium.
 5. Thevalve according to claim 1, wherein the noble metal layer is about 0.7μm to about 1.3 μm thick.
 6. The valve according to claim 1, wherein thetertiary layer comprises silver.
 7. The valve according to claim 1,wherein the tertiary metallic metal layer is about 0.25 μm to about 250μm thick.
 8. The valve according to claim 1, wherein the strike layercomprises a silver layer that is about 0.1 μm to about 2.5 μm thick. 9.A wear plate of a valve including a component, the wear platecomprising: a surface disposed in sliding engagement with a surface ofthe component, the surface of the wear plate comprising: a substrateincluding corrosion resistant steel; a secondary layer disposed on asurface of the substrate; a noble metal layer disposed on a surface ofthe secondary layer; a tertiary layer disposed on a surface of the noblemetal layer; and a strike layer interposed between the noble metal layerand the tertiary layer.
 10. The valve according to claim 9, wherein thenoble metal layer comprises at least one or more of gold, platinum,palladium, rhodium and combinations thereof.
 11. The valve according toclaim 9, wherein the secondary layer is about 0.25 μm to about 25 μm andthe noble metal layer is about 0.7 μm to about 1.3 μm thick.
 12. Thevalve according to claim 9, wherein the tertiary layer comprises silver.13. The valve according to claim 9, wherein the tertiary layer is about0.25 μm to about 250 μm thick.
 14. The valve according to claim 9,wherein the strike layer comprises a silver layer that is about 0.1 μmto about 2.5 μm thick.
 15. A butterfly valve, comprising: a valvehousing formed to define a bore; a disc and shaft set operably disposedin the bore, the disc and shaft set including a wear plate disposed inabutment with a shim; and an actuator coupled to the disc and shaft setto thereby cause the disc and shaft set to rotate about a long axis ofthe shaft such that a surface of the wear plate slidably engages with aflange surface of the shaft, the surface of the wear plate comprising: acorrosion resistant substrate; a secondary layer disposed on a surfaceof the corrosion resistant substrate; a noble metal layer disposed on asurface of the secondary layer; a tertiary layer disposed on a surfaceof the noble metal layer; and a silver strike layer that is about 0.1 μmto about 2.5 μm thick interposed between the noble metal layer and thetertiary layer.
 16. The valve according to claim 15, wherein the wearplate comprises flanges that extend radially outwardly from an outerdiameter of the wear plate at opposite sides thereof.
 17. The valveaccording to claim 15, wherein the corrosion resistant substratecomprises corrosion resistant steel, the secondary layer is about 0.25μm to about 25 μm and comprises nickel, the noble metal layer is about0.7 μm to about 1.3 μm thick and comprises at least one or more of gold,platinum, palladium and rhodium and the tertiary layer is about 0.25 μmto about 250 μm thick and comprises silver.